I got curious myself and agreed, so I went looking.
A lot of sources specified that it was part of a technical requirements checklist, and…
Yeap. It doesn’t explicitly require a “press any key” screen, but it gives a more pleasant screen to look at while you select a user. People online also say it’s used to detect which controller is in use.
If you add a feature like this to a game, it becomes harder to maintain if there are discrepancies between builds. So presumably it’s usually just left in rather than removed.
So I’ve been reading through this study and comparing it to modern health advice. For the most part, the 22% of energy threshold seems to be above 1.2-1.6 grams of protein per kg of body weight (for active individuals).
The functional advice is: following the guidelines from the FDA will keep you out of the risks outlined in the study.